Quadrant baffle for heat exchange header



March 16, 1965 R. E. ALLENDER QUADRANT BAFFLE FOR HEAT EXCHANGE HEADER 2Sheets-Sheet 1 Filed NOV. 21, 1962 INVENTOR. RICHARD E. ALLENDERATTORNEY March 16, 1965 R. E. ALLENDER 17 QUADRANT BAFFLE FOR HEATEXCHANGE HEADER Filed Nov. 21, 1962 2 Sheets-Sheet 2 INVENTOR. RICHARDE. ALLENDER BYWC4U? ATTORNEY United States Patent Ofiice 3,1 3,482Patented Mar. 16, 1965 3,173,482 QUADRAN'I' RAFFLE FGR AT EXCHANGEHEADER Richard E. Allender, Davenport, Iowa, assignor to American AirFilter Company, Ina, Louisville, Ky, a corporation of Delaware FiledNov. 21, I962, Ser. No. 23%,227 II Claims. (til. 165-174) coil; a returnchamber is formed which communicates with the row of tubes on theopposite face of the coil; and one or more flow reversing chambers areformed to place each even numbered row of tubes in communication withthe next adjacent odd numbered row of tubes, save for the first and lastrow of tubes.

The header, in one presently preferred embodiment for afour row coil,includes a shallow pan-shaped member receiving the open ends of thetubes, a channel secured with its open side over the two middle rows oftube ends to direct the flow out of one of. these rows into the other ofthese rows, baffie means including opposite quadrant portions secured tothe open face of the pan-shaped membet and overlapping the channel, thebatlie means further including an intermediate outwardly. projectingflange in a plane normal to the quadrant portions and extending atransverse to the direction in which the channel extends, and a pair ofshallow pan-shaped cover members secured over the quadrant portions andremaining open face portions of the first pan-shaped member. In thispreferred embodiment, and considering the coil as disposed with the tuberows being in avertical plane and the tubes running in a horizontaldirection, the intermediate flange serves as a partition which dividesthe header outer half (with respect to its depth or thickness) into alower supply chamber, and an upper return chamber. The channel and onequadrant baffle prevents the flow of Water (or other tempering mediumused) which enters the supply or lower chamber from entering the tubeends of any row of tubes except the row along one face of the coil, andthe channel and opposite quadrant baffle in the upper chamber preventflow leaving the row along the opposite face of the coil from passinganywhere other than out of the return tapping. The channel over the twoinner tube row ends directs flow from the one to the other row of tubes.

One feature of the outlined header construction is that the supply andreturn connections to the header may be positioned anywhere on therespective opposite portions of the outer half. When the coil is to beinstalled under conditions where the piping location is restricted, thisfeature is distinctly advantageous since the restricted location doesnot preclude installing the coil to obtain a counterilow passage ofwater. Other advantages will be noted in connection with the followingdescription, which is to be taken in connection with the drawing whereinthe figure generally follow the sequence of assembly of the header andwherein:

FIGURE 1 is a face view of the inner shell which receives the tube ends;

FIGURE 2 is a side view, with fragments of the tubes beingshown, of theinner shell of FIGURE 1;

FIGURE 3 is a view corresponding to FIGURE 1 but with the return channelinstalled to place the two center rows of tubes in communication witheach other;

FIGURE 4 is an enlarged horizontal section correspending to one takenalong the line 4-4 of FIGURE 3; FIGURE 5 is a view corresponding toFIGURE 3 but with baflle means added;

FIGURE 6 is a side view of the assembly of FIGURE 5; FIGURES 7 and 8 areisometric views of thebaflle means used for a right-hand and left-handcoil respectively;

FIGURE 9 is an isometric view of cover means carrying the supply andreturn tappings, and adapted to be Se.-v

cured against the face of the FIGURE 5 assembly;

FIGURE 10 is an outer face view of the header in,com-

pleted form;

FIGURE 11 is a side View of the completed header of FIGURE 10;

FIGURE 12 is a fragmentary isometric view of the header, with partsbroken away to illustrate the tempering fluid flow through the headerand tubes;

FIGURE 13 is a sectional view illustrating the return channelarrangement in a sixrow coilheader.

Only the header end of the coil is shown in the drawing. The remainderof the coil may be assumed to be conventional. Thus at the end of thecoil opposite the header, the usual return bends are provided so thatthe.

FIGURES 1, 2, 4Irmer section and tube assembly The inner or tubereceiving section 2 of the header has the general shape of a rectangularshaliow pan and includes a perimetric flange 4 and a sunken or recessedwall 6 in which rows of extruded holes are provided to receive the endsof the corresponding rows of tubes 8. In most cases conventional fins 10are assembled on the tubes in spaced relation, and a support plate (notshown) may be provided between the wall 6 and first fin. The tube endsare brazed to the wall 6 by directing the brazing flame or other heatingmeans toward the open ends of the tubes (i.e., the brazing is done fromthe open or right side of the wall a with respect to FIGURE 2). The openaccess thus afforded is considerably more convenient for brazing than inthe case of brazing multiple rows to the exterior face of a closedheader. Also, since no brazing access to, the exterior face of the Wall6 is required the fins or support plate may be positioned closelyadjacent that exterior face.

It is also noted that the extruded holes in wall 6 which receivethe tubeends are formed with the material around the holes displaced outwardlyso that an annular well 11 (shown in FIGURE 4 only) is formed with thetube end wall to facilitate the brazing operation.

F GURES 3 and 4Rezfum channel installation A return channel 12 is placedin the pan-shaped section 2 to straddle the two center rows of tubeends, and is brazed along all edges to the section 2 to isolate the tubeends of the two center rows from the rest of the header interior. Thechannel extends the length of the sunken Wall 6 and the legs of thechannel are dimensioned and inclined so that the outer face of thechannel bight lies in the same plane as the outer face of perimetricflange 4 of section 2. The oblique disposition of the legs of thechannel relative to the bight is preferred to promote smooth flow of theWater within the header.

FIG URES 58Bafile means installation At that stage of assembly when onlythe return channel 12 has been installed, the coil may be considered tostill be universal from the standpoint of the coil may ultimately bedisposed with its supply and return connections on either the right-handend of the left-hand end of the coil. However, before installation ofthe baffle means illustrated in FIGURES 7 and 8, it must be knownwhether the supply and return connections are to be on the right-hand orleft-hand end. Assuming that the flow of tempering medium in the coil isto be counterflow to the air through the coil, then the FIGURE 7 bafilemeans is used for a right-hand coil, and the FIGURE 8 baffle means isused for a left-hand coil. If for some reason parallel flow were desiredthen the FIGURE 7 bafiie means would be used for a left-hand coil, andthe FIGURE 8 baflle means for a right-hand coil. It is usuallypreferable that the flow of tempering medium in relation to thedirection of air flow be what is called counterflow, i.e., the mediumflows through the row of tubes on the air leaving face first and thenbows through rows of tubes successively closer to the air entering face,since this promotes heat exchange. In FIGURE 5 the arrows along theleft-hand edge of the coil indicate the direction of air flow forpurposes of explanation herein, and since one facing in the direction ofair flow would see that the header is on the right end of the coil, thecoil of the present example may be considered as a right-hand coil.

In FIGURES 5 and 6 the bafiie means of FIGURE 7 is shown in installedposition on the open face of inner section 2 and on the bight of thechannel 12. The FIG- URE 7 baflie means includes a first quadrantportion 14, a third quadrant portion 16 and an intermediate outwardlyprojecting flange 18. The flange 18 separates the outer half of theheader into a top half and a bottom half. The first quadrant 14 overliesthe corresponding first quadrant of the section 2 and thus bridges thespace between the return channel 12 and the perimetric flange 4. Thethird quadrant portion 16 correspondingly overlies the third quadrant ofthe section 2. At this point in the assembly of the header, those edgesof the first and third quadrant baffles which lie on the bight of thereturn channel 12 are brazed to it, and the central portion of the loweredge of the intermediate flange 18 is brazed to the adjacent bightsurface. It is not necessary to braze along the perimetric flange 4 ofthe section 2 at this time.

If the coil were to have the supply and return on the left end and becounterflow, the baflle means shown in FIG. 8 would be used instead ofthe FIG. 7 baffle means. In such a case, the battle portions 20 and 22would be in the second and fourth quadrants respectively of FIG. 5, withthe intermediate flange 24 projecting outwardly the same as with theFIG. 7 part. Either a right-hand or a left-hand baflle means may beformed from any one blank, the only difference being the direction inwhich the quadrant baflle portions are rotated relative to the flangeduring breaking.

FIGURES 911End cap means installation After the baffle means has beeninstalled and secured by brazing, the outer half of the header is closedby the addition of an upper and a lower end cap 26 and 28 respectively.They are like section 2, with which they mate in assembled form, in thatthey are relatively shallow and pan-shaped. Each includes a perimetricflange 30 along three edges, 2. main wall portion 32, and aninwardlydirected stub flange 34 along the fourth edge. While theconstruction of both caps is the same, they may well differ in thelocation of the tapping provided on each. In the illustrated coil forexample, both the supply tapping 36 on the lower end cap 28 and thereturn tapping 38 on the upper end cap 26 are disposed toward the frontface (i.e., air entering face) of the coil. The exact location of thetappings on the walls is dictated by the supply and return pipinglocation of the installation where the coil is to be used.

The end caps 26 and 28 are placed against the inner section 2 and bafliemeans with the stub flanges 34 abutting and separated by theintermediate flange 18. The end caps are secured by brazing theperimetric flange 30 of each end cap to the perimetric flange 4 of theinner section, and by also brazing the stub flanges 34 to theintermediate flange 18. Of course, at the same time that the perimetricflanges are brazed, the edges of the opposite quadrant baffle portionssandwiched between these flanges are brazed so that the perimeter of theheader is completely sealed.

In its finally assembled form the plane in which the opposite quadrantbaflie portions 14 and 16 lie may be considered as splitting the depthof the header into an inner half and an outer half. The channel 12splits the inner half into separate spaces extending for the height ofthe tube rows, and the flange 18 splits the outer half in the oppositedirection into the lower supply space 28 and upper return space 26. Thespace in communication with the supply tapping 36 thus includes thatpart of the outer half below flange 18, and that part of the inner halfon the right side of the return channel 12. Correspondingly, the spacein communication with the return tapping 38 includes that part of theouter half above flange 18, and that part of the inner half on the leftside of the return channel 12. The right row of tubes (last row withrespect to the direction of air flow) is open to the inner half space onthe right of channel 12, and the left row of tubes (first row withrespect to air flow) is open to the inner half space on the left of thechannel.

FIGURE 12Fl0w paths The flow path is perhaps best perceived from theFIG- URE l2 illustration. As illustrated, the supply water enters thesupply chamber 23 through the supply tapping 36 (not shown in FIG. 12)and flows over the third quadrant bafile portion 16 and over the bightof the return channel 12 to the tube ends of the last row of tubes. Thesupply water also flows underneath the edge of intermediate flange 18and under the first quadrant baflle portion 14 so that the entire lastrow of tubes is supplied with water. The water flows down through all ofthe tubes of the last row to the opposite end return bends connectingeach fourth row tube to the corresponding third row tube (bends notshown), and then back up through all of the third row of tubes into thespace formed between the return channel 12 and the inner section 2. Herethe water reverses its direction again and flows back down through allof the tubes of the second row, through the return bends (not shown)connecting the second and first rows and back up all of the tubes of thefirst row to the space on the left side of the channel. That watercoming into the space in the inner half between the third quadrantbaffie portion 16 and the inner section 2 flows underneath the edge ofthe intermediate flange 18 into the second quadrant of the header, intothe return chamber 26 and out of the return tapping along with the waterreturning directly to the second quadrant space.

FIGURE 13-Six row coil The principles of the invention may be applied toany same end supply and return coil which has an even number of rows oftubes. As shown in FIGURE 13, if the coil has six rows of tubes thereturn channel means 40 is designed to form a double chamber to placethe tube ends of the second and third rows, and fourth and fifth rows,in isolated communication. The first and sixth row tube ends are ofcourse in communication with the return and supply chamber respectivelyas set forth in connection with the four row coil.

Miscellaneous With a coil header constructed in accordance with theprinciples set forth herein, it will be appreciated that a good deal offlexibility is permitted in locating the supply and return tappings onthe outer face of the header Without requiring a change in the flowsequence through the rows. One example of the advantages of thisflexibility is found in the use of the described coil in an airconditioning unit ventilator in which it is desirable to have both thesupply and return tappings toward the front face of the coil because ofavailable piping space, and still obtain a counterflow path of thetempering medium. A coil with a header incorporating the principles ofthe invention may be disposed in various ways so long as recognizedpiping practices regarding drains, air vents, etc., are followed. Thus,if the return tapping is not provided at the highest point of the returnchamber, an air vent should be provided. Small weep holes are preferablyprovided in the interior partitions to permit draining of the entirecoil. For a coil which is to be installed in an inclined position, theholes 42 in the opposite quadrant baffles (FIGS. 7 and 8), and holes 44in the lower end of the return channel (FIGS. 3 and 5), will permitcomplete draining into supply chamber 28.

While the invention has been described as embodied in one preferredconstruction, various departures in detail may be made without departingfrom the scope of the invention. For example, the respective quadrantbafile portions are shown as being of equal size and as being anintegral part of a single piece bent to form both of the balflequadrants and the intermediate flange. Such an arrangement is presentlypreferred because of manufacturing economies effected thereby. Ofcourse, these pieces could be separate. As a further example of a changewithin the scope of the invention, one quadrant portion could be ofgreater area than another if it were desirable to divide the outer halfof the header into spaces of unequal size in connection with pipinglocation limitations.

The invention claimed is:

1. A header construction for a same end supply and return serpentinecoil having an even number of rows of tubes, comprising:

(a) a header plate having apertures receiving the open ends of saidtubes;

(b) channel means forming successive chambers with said header plateover the tube ends of each two successive adjacent rows of tubes,exclusive of the first and last rows of said tubes, so that said eachtwo successive adjacent rows of tubes are in communication but isolatedfrom other rows; and

() cover means, and interior opposite quadrant bafiie means lying in aplane splitting the thickness of said header, sealed to said headerplate and channel means to form an outer supply chamber in communicationwith said first row, and a separate outer return chamber incommunication with said last row.

2. A header construction for a same end supply and return serpentinecoil having an even number of rows of tubes, comprising:

(a) a shallow pan-shaped member having apertures receiving the open endsof said tubes;

(b) return channel means disposed to straddle the tube ends of each twosuccessive adjacent rows of tubes, except the first and last of saidrows, to place said tube ends of each two successive adjacent rows incommunication;

(c) bafile means overlapping said return channel means and coveringopposite quadrant portions only of said pan-shaped member;

(at) partition means projecting outwardly in a plane separating saidbaflie means and extending in a direction generally transverse to saidreturn channel means; and

(e) cover means enclosing the outer part of said header and sealed tothe perimeter of said pan-shaped member and said partition means to forma supply chamber on one side of said partition means in communicationWith said first row of tubes, and a return chamber on the opposite sideof said partition means in communication with said last row of tubes.

3. A header construction for a same end supply and return serpentinecoil having an even number of rows of tubes, comprising:

(a) a header plate having apertures receiving the open ends of saidtubes; 7

(b) channel means isolating the ends of successive adjacent rows oftubes into communicating pairs which are out of communication with theends of the first and last row of tubes;

(c) flow baffle means including opposite quadrant bafile portions and anintermediate outwardly projecting flange, one of said bail-"1e portionsoverlying part of the tube ends of said first row and the other of saidbafile portions overlying part of the tube ends of said last row; and

(d) end cap means sealed to the perimeter of said header plate and tosaid flange to provide separate supply and return chambers on oppositesides of said flange respectively in communication with the ends of saidfirst and said last tube rows.

4. A header construction for a same end supply and return serpentinecoil having an even number of tube rows, comprising:

(a) a hollow structure formed of a tube end receiving inner shell havingapertures receiving the open ends of said tubes and mating outer shellmeans;

(15) return channel means secured to the inner face of said inner shellconnecting each even numbered tube row to the adjacent odd numbered tuberow, save for the first and last tube rows; and,

(c) baffle means in said structure dividing the remain der of theinterior space into a supply chamber and a return chamber incommunication with said first and last tube rows respectively, saidbafiie means including opposite quadrant baflle portions lying in theplane dividing said inner shell and said outer shell means, and crosspartition means projecting outward- 1y from said plane to separate saidouter shell means into opposite spaces respectively in communicationwith said first and said last tube rows.

5. The header construction of claim 4 wherein the in terior spacebetween each quadrant bafiie portion and its facing inner shell surfaceis in communication with the interior space between the other quadrantbaffle portion and its facing outer shell means surface.

6. A header construction for a same end supply and return serpentinecoil having an even number of tube rows, comprising:

(a) means forming a hollow, relatively shallow, generally rectangularheader having said tubes received in apertures in one face, and supplyand return openings in the opposite face;

(b) return channel means positioned against the inner surface of saidtube receiving face to place each even numbered tube row incommunication with the adjacent odd numbered tube row, save for thefirst and last tube row;

(0) opposite quadrant bafiies lying in a plane dividing the depth ofsaid header, said baflles overlapping said return channel means; and

(a') an intermediate flange, in a plane normal to said plane dividingthe depth of said header, extending generally transverse to said returnchannel means, and projecting outwardly to said opposite face of saidheader between said supply and return openings.

7. The header construction of claim 6 wherein:

(a) said baffles and said intermediate flange comprise single sheetmember with said opposite quadrant baffles broken in one direction fromsaid flange for a right hand coil, and in an opposite direction for aleft hand coil.

8. A header construction for a same end supply and return serpentinecoil having an even number of rows of tubes, comprising:

(a) an inner pan-shaped section, and a pair of outer pan-shapedsections, secured together in opposing relation to form a hollow header,the wall of said inner section having apertures receiving the open endsof said tubes in parallel rows, and the opposite walls of said outersections including a supply and a return opening;

(b) return channel means overlying the open ends of said rows of tubes,save for the first and last rows, to place each even numbered tube rowin communication with the adjacent odd numbered tube row;

(0) a pair of opposite quadrant bafiies disposed in the plane betweensaid inner section and said outer section, each of said baffles havingits edge parallel to said return channel means overlapping said returnchannel means; and

(d) an intermediate flange extending transverse to said return channelmeans and projecting outwardly from the plane in which said baflies lieto divide said outer sections into separate chambers, one of whichcontains said supply opening and communicates with said first row oftubes, and the other of which contains said return opening andcommunicates with said last row of tubes.

9. The header construction of claim 8 wherein:

(a) the depth of said return channel means corresponds generally withthe interior depth of said inner section.

10. The header construction of claim 8 wherein:

(a) the legs of said return channel means lie in planes forming anopening angle. 11. The header construction of claim 8 wherein: (a) saidopposite quadrant baffles and said flange comprise an integral member.

References Cited by the Examiner UNITED STATES PATENTS 1,796,509 3/31Daley 165-158 20 CHARLES SUKALO, Primary Examiner.

1. A HEADER CONSTRUCTED FOR A SAME END SUPPLY AND RETURN SERPENTINE COILHAVING AN EVEN NUMBER OF ROWS OF TUBES, COMPRISING: (A) A HEADER PLATEHAVING APERTURES RECEIVING THE OPEN ENDS OF SAID TUBES; (B) CHANNELMEANS FORMING SUCCESSIVE CHAMBERS WITH SAID HEADER PLATE OVER THE TUBEENDS OF EACH TWO SUCCESSIVE ADJACENT ROWS OF TUBES, EXCLUSIVE OF THEFIRST AND LAST ROWS OF SAID TUBS, SO THAT SAID EACH TWO SUCCESSIVEADJACENT ROWS OF TUBES ARE IN COMMUNICATION BUT ISLOATED FROM OTHERROWS; AND (C) COVER MEANS, AND INTERIOR OPPOSITE QUADRANT BAFFLE MEANSLYING IN A PLANE SPLITTING THE THICKNESS OF SAID HEADER, SEALED TO SAIDHEADER PLATE AND CHANNEL MEANS TO FORM AN OUTER SUPPLY CHAMBER INCOMMUNICATION WITH SAID FIRST ROW, AND A SEPARATE OUTER RETURN CHAMBERIN COMMUNICATION WITH SAID LAST ROW.